1. Field of the Invention
The present invention relates to a film feeding apparatus for feeding a film from a film roll on a supply reel to a take-up reel, and more particularly, it relates to such a film feeding apparatus applicable to various microfilm readers having different mirror arrangements.
2. Related Background Art
Up to the present, in microfilm readers or reader printers, because of the limitations of the size of the apparatus and/or the arrangement of optical elements, a bent optical path through which image light passes has been formed by using a plurality of mirrors. As such apparatuses, a reader P having a mirror arrangement comprising four (even) mirrors m.sub.1 -m.sub.4 as shown in FIG. 12A and a reader Q having a mirror arrangement comprising three (odd) mirrors m.sub.1 -m.sub.3 as shown in FIG. 12B have been known. In each of these readers, a film F.sub.o loaded within a film feeding apparatus is illuminated by a lamp L, to obtain a light image which is then projected onto a screen 101P or 101Q through the mirror arrangement m.sub.1 -m.sub.4 or m.sub.1 -m.sub.3 so that frame images on the film can be easily retrieved. Thereafter, the film F.sub.o is rewound on a reel 102 by rotating the latter by means of a motor. The film feeding apparatus 100 is so designed that it can be removably mounted on the reader, whereby the apparatus is applicable to various readers.
However, in the above-mentioned conventional arrangements, since the light image from the film F.sub.o is directed to the screen 101P or 101Q through the plurality of mirrors, the image projected on the screen 101P through the even number of mirrors is proportional to the image on the film, but, the image projected on the screen 101Q through the odd number of mirrors will be inverted with respect to the image on the film. Accordingly, in order to obtain the normal image projected on the screen 101P or 101Q both in the case of the reader P having four mirrors m.sub.1 -m.sub.4 (FIG. 12A) and in the case of the reader Q having three mirrors m.sub.1 -m.sub.3 (FIG. 12B), the film F.sub.o must be mounted on the reader Q with the surface of the film turned over.
In this case, in order to turn the film F.sub.o over at the illuminating position, i.e., in order to provide the back surface of the film at the illuminating position, the reel 102 on which the film F.sub.o is wound may be mounted on a supplying shaft of the film feeding apparatus 100 with the reel itself turned over. Accordingly, when the reel 102 on which the film is wound is applicable to the reader P having the even number of mirrors as it is, if the reel 102 is mounted on film feeding apparatus after it has been turned over, it is possible to project the normal image on the screen 101Q in the reader Q having the odd number of mirrors as shown in FIG. 12B.
However, in such a film feeding apparatus 100, since the reel 102 can be rotated only in a clockwise direction during the rewinding operation of the film, if the reel 102 is loaded with the turned-over condition as shown in FIG. 12B, the reel 102 cannot be rotated in an anti-clockwise direction, with the result that the film F.sub.o cannot be rewound. Therefore, such film feeding apparatus 100 cannot be applied to the reader having the odd number of mirrors. If the rewinding direction of the film is set to an opposite direction (i.e., anti-clockwise direction), such film feeding apparatus will not be applied to the reader having the even number of mirrors.